It may sound obvious but you and the midwife are essential, everyone else is an optional extra, depending on circumstances. You may want a partner, relative or friend (two are usually plenty, to give each other a break from time to time). If everything progress normally, that will be all. If things have become complicated, an obstetrican may need to be there. If the baby is thought to need specialist help on delivery, a paediatrician may also be present. A second midwife may come in to help at the request of your midwife.